Ethernet controllers are provided to facilitate data communication over a network in accordance with a defined transport protocol. The ethernet controllers are typically included in a network interface card (NIC) which interfaces through a port on a PC or similar device to a transmission medium. This transmission medium could be a fiber optic medium, a coaxial cable medium or a twisted wire pair medium. Each of these mediums requires a corresponding transceiver to interface the data thereto. The transmission medium will then provide a connection to another NIC on the system, typically at a hub. This constitutes the other end of the connection, such that a dedicated connection will be provided between two NIC cards.
For the twisted wire pair interface, a transformer is typically utilized on both the transmit side and the receive side to effectively isolate the transceiver from the transmission line itself. The purpose for this is to ensure that a defined DC voltage is present at each end of the transmission line and also to ensure that any high voltages present on the transmission line, due to static electricity and the such, are not coupled through to the input of the transceiver, which is typically in an integrated circuit. The specifications for this protection, i.e., referred to as an isolation barrier, requires that it withstand 2,000 volts. However, the transformers can become rather complex and constitute a substantive portion of the cost of a NIC. With the present high speed ethernet controllers, such as the 1000BASE-T ethernet controllers, the complexity of the transformers is due, in part, to the fact that they require hand wound transformers. Further, for restricted form factors, the size of the transformer can be an impediment.